This invention relates to a braking device for wheels of vehicles, particularly vehicle trailers, having a caliper and brake linings guided therein, between which at least one brake disk is arranged which is axially displaceable in a non-rotatable manner with respect to the wheel, and having a preferably pneumatically operable adjusting device. An exclusively rotationally movable drive shaft is used as the mechanical transmission element for generating a pressure of the brake linings onto the brake disk.
From European Patent Document EP 0 136 434 B1, a brake for a vehicle wheel is known which has a floating caliper which comprises several brake disks and an adjusting device with an axially displaceable drive shaft. The brake disks are displaceably held on a toothing of a wheel hub.
It is an object of the invention to provide a braking device for wheels of vehicles, particularly of vehicle trailers, which has a compact and small construction, ensures an optimal efficiency and is easy to service.
According to the invention, this object is achieved by constructing a brake caliper as a fixed caliper and having only one of the brake linings arranged on opposite sides of the brake disk carry out an application movement when the adjusting device is operating.
The principal advantages achieved by the invention are that the caliper of the device is constructed as a fixed caliper so that a small installation space is required and the caliper is light in weight, compact, and provided with an adjusting device. The adjusting device can preferably be operated pneumatically or, as an alternative, also hydraulically. The caliper can easily be fastened to the axle tube by a fastening element such as, for example, a weld, creating a linkage which projects freely toward the end of the wheel hub.
The mechanical adjusting device, such as a ball screw, is to be fastened on the caliper, together with pressure pistons operatively connected by way of a yoke. The adjusting device forms a compact constructional unit which is surrounded, for example, by a housing and is thus protected from damaging outside influences.
In particular, the ball screw spindle is axially non-displaceably arranged with respect to a steering knuckle, which has an advantageous effect on the required receiving space and simplifies the power transmission as well as the pivot bearing. A demounting or repair of the adjusting device can take place in a simple manner by removing the housing.
In order to achieve a uniform pressure distribution on the brake linings of the brake and a corresponding application movement during the braking operation, at least one pressure piston, respectively, is provided on each side of the ball screw spindle of the adjusting device. These pressure pistons are advantageously operated by the connecting one-part yoke with the same force via the spindle. An axial movement is transmitted to the yoke by way of the ball screw and therefore also to the pressure piston. The pressure pistons are axially guided during adjustment by interior guide pins so that a mutually nested guide which is protected against outside influences is obtained and an axial guiding of the pressure pistons is ensured in every case.
The support of the spindle preferably takes place in a bearing of a bearing plate of the caliper which forms an abutment and furthermore by way of a bearing in the housing neck so that sufficient support is provided. Support of the spindle can also take place in the neck or at the outlet of the housing which then forms the abutment. Thus, a virtual reversal of the power flux is achieved with respect to the other construction with the bearing plate.
The bearing plate is simultaneously provided with lateral, projecting and stepped legs. These are used for fastening on the fastening element which is connected with the wheel axle, for example, by welding. As a result, a simple mounting or demounting of parts of the braking devices, such as a one-part or multi-part caliper, can be carried out. In this case, the adjusting device, and more particularly the drive shaft or the ball screw spindle, is also easy to repair and mount or demount. The fastening element preferably closes off flush with the bearing plate.
The ball screw spindle is preferably offset in an approximately axially parallel manner with respect to an axis of rotation of the brake disk. This results in a small-sized and easily accessible braking device.
Between its bearing plate and its support plate, the caliper has a caliper bridge with opposite guiding edges for the brake linings. These guiding edges are constructed as slideways. The brake disks, which are arranged in front of and/or behind the brake linings during the braking operation, can therefore be displaced by the pressure pistons by way of the adjusting device against the caliper or against the supporting plate of the caliper. For this purpose, the brake disks are held on the wheel hub in a driving toothing, particularly in an involute toothing, and can be displaced on the hub in a sliding manner.
Depending on its type and application, the braking device may comprise one or several brake disks. The brake disks may be constructed as solid disks or as internally ventilated brake disks. The brake linings are constructed so as to correspond to the number of brake disks.
The adjusting device may also comprise only one pressure piston which will then be arranged coaxially with respect to the spindle. Furthermore, it is conceivable to use more than two pressure pistons when the brake lining has a particular size.